A turbomachine, such as a gas turbine, generally includes an inlet section, a compressor section, a combustion section that includes a plurality of combustors, a turbine section and an exhaust section. The inlet section cleans and conditions a working fluid (e.g., air) and supplies the working fluid to the compressor section. The compressor section progressively compresses the working fluid and supplies a high pressure compressed working fluid to the combustors where it is mixed with a fuel and burned in a combustion chamber to generate combustion gases having a high temperature and pressure. The combustion gases flow along a hot gas path into the turbine section where they expand to produce work. For example, expansion of the combustion gases in the turbine section may rotate a shaft connected to a generator to produce electricity.
During operation of the gas turbine, various components in the system are subjected to high temperature flows, in particular those components along the hot gas path. Such components are typically known as hot gas path components. The hot gas path components include the combustors and components of the turbine section. Each combustor includes various hardware components. For example, a conventional gas turbine combustor may include one or more fuel nozzles, a combustion liner, a cooling flow sleeve, a transition duct, an impingement sleeve, a cap assembly and/or various mounting hardware such as brackets and radial compression or hula seals. The turbine section generally includes various hardware components that come into direct or indirect contact with the hot combustion gases such as stator vanes, stationary shrouds, rotatable turbine blades, and rotor disks.
Over time, various factors including thermal cycling, vibrations and/or pressure pulses within the gas turbine may result in hardware component degradation. As a result, regularly scheduled outages for inspection and repair must be executed, thus affecting machine availability.
However, in some instances, unplanned outages may be necessary, such as when a hardware component requires maintenance or repair prior to the next regularly scheduled outage. Outages can be detrimental to the efficiency and profitability of a power plant or other gas turbine operation, especially unplanned outages. Thus, there exists a need for a system and method for operating a gas turbine which optimizes the hardware component life to avoid or minimize unplanned outages.